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        검색결과 76

        41.
        2013.07 서비스 종료(열람 제한)
        As the drought is getting worse, Lot of studies related to drought stress in plant have been conducted. Recently whole genome sequencing of Brassica rapa ssp which is important vegetable crop to East Asians has been completed to enable Omic research. It is known that the drought damages occur in the early stage of plant development. Here, we performed shotgun proteomics analysis of B. rapa to observe the morphological characters, monitor the expression patterns of the identified proteins during drought stress, and detect the proteins related to drought stress. The three week old B. rapa grown in density of single plant in a single pot were used. Drought stress were treated as that a single plant in soil was removed from the pot and the plant with soil was exposed to air and light without watering. Leaves were immediately harvested before drought treatment, 24hr after drought treatment, and 48hr after drought treatment. The protein expression patterns were monitored by a quantitative shotgun proteomics analysis. Extracted proteins were separated in 1D-SDS-PAGE then the gel sliced into seven pieces. Chopped gels were ingel-digested. Peptides were assigned to mass spectrometry (Q-Exactive). The ms/ms spectra were analyzed through Proteome Discoverer. By combining all of the identified proteins in the seven sliced gel samples, total B. rapa proteome reference map was completed. Protein expression patterns were investigated by comparing the quantity of protein. With shotgun proteomic approach, we evaluated the changes in the quantity and finally discovered the candidate proteins related with drought stress.
        42.
        2013.07 서비스 종료(열람 제한)
        Low temperature is a major factor restrict to growth and limiting productivity of rice crops. We used a cDNA microarray approach to monitor the expression profile of rice (Oryza sativa) under chilling stress and identified 20 chilling inducible genes in previously study. Ten such genes encoding bHLH, metal transporter and, zinc finger protein with unknown functions showed a significant change in expression under various abiotic stresses. Among them, OsCHI1 (Os07g15460), OsCHI2 (Os02g43660), and OsCHI3 (Os01g61160), were selected for further study. They have structural features such as metal-binding signature sequences in their protein sequences, and OsCHI genes were expressed in root of rice seedling and induced in chilling and salt or drought. Expression of OsCHI1, OsCHI3 and OsCHI2 were targeted to membrane and ER when transiently expressed in tobacco cell, respectively. The Arabidopsis (Arabidopsis thaliana) transgenic plants overexpressing showed increased tolerance to salt and drought stress in the seed germination and root elongation than that of wild type. This comprehensive study provides insight into the biological function of OsCHIs, which may be useful in understanding how rice plants adapt to unfavorable environmental conditions.
        43.
        2013.07 서비스 종료(열람 제한)
        Drought and salinity are the major abiotic stresses which are being continued to hamper the ecosystem and agriculture of the affected region. Plant species have adaptations to enhance their ability to tolerate stresses through physiological adjustment. Therefore, substantial amount of research are ongoing to provide insights about those mechanisms which enlighten the stress tolerance in plant. In this study, several rice cultivars were collected from the different parts of the world and ion accumulation experiments were conducted to select the best stress tolerant cultivar in drought and salt stress environment. For stress treatment, five rice cultivars were subjected to salt (200 mM NaCl) and drought (200 mM Mannitol) for 72h. Later Na+, Ca++, K+ concentrations in shoot and root samples were examined at different time interval. In both drought and salt stress, rice cultivar C201 (collected for uzbekistan) showed the lowest levels of Na+ ion and Na+: K+ ratio compared to other cultivars. It was significant parallel observation with pokkali (known salt tolerant cultivar). In this preliminary study, it was observed the C201 had more stress tolerant in terms of ion accumulation; however detail physiological studies are required to strengthen the idea regarding the best stress tolerant physiotype.
        44.
        2012.07 서비스 종료(열람 제한)
        Tocopherols (α-, β-, γ- and δ-tocopherols) represent a group of lipophilic antioxidants which are synthesized only by photosynthetic organisms. It is widely believed that protection of pigments and proteins of photosynthetic system and polyunsaturated fatty acids from oxidative damage caused by reactive oxygen species (ROS) is the main function of tocopherols. In the present study, NtTC, which encodes a tobacco tocopherol cyclase ortholog, was cloned and characterized. Compared with control plants, NtTC transgenic rice showed higher tolerance to drought stress, and total tocopherol content increased by 52 % in leaf. Additionally, total antioxitant activity of NtTC transgenic lines was increased significantly by 19%. These results demonstrate that over-expressing NtTC could improve the tolerance to abiotic stress in rice, and tocopherols play a crucial role in the protection of oxidative stress.
        45.
        2012.07 서비스 종료(열람 제한)
        Environmentally inflicted stress (abiotic stress) such as high drought stress could be limiting the plant productivity. The mechanism of drought stress signaling in plant related with anti-apoptosis has not yet been full described. Understanding drought stress signaling is key to producing drought-tolerant plant. In this study we recently have identified Oryza sativa genes related abiotic stress water deficit. Abiotic stress related genes were screened from Oryza sativa cDNA library and identified gene by yeast functional screening. The yeast expression showed that they east cell grow well on SD-galactose-Leu-Ura-. The screening of over than 7000 clones from Oryza sativa cDNA libraries has been identified. 28 clones that survived following BAX-expression on inducible galactose medium. R12H780 clones confirmed protein prediction like putative senescence-associated-protein. This gene contains an open reading frame (ORF) of 108 amino acids. Transcription of R12H780 was induced in response to drought stresses, RT-PCR analysis showed transcript level in plant strongly detected in earliest time of drought stress treatment. Yeast transformed with R12H780 gene displayed markedly improved tolerance to PEG treatment, and high salinity in comparison to the control yeast (vector only). The results indicate R12H780 expression represents a new type of drought stress related gene with anti-apoptotic in Oryza sativa and endows tolerance to several types abiotic stress.
        46.
        2012.07 서비스 종료(열람 제한)
        Transgenic cymbidium plants containing drought and salt stresses tolerance genes were produced by using a highly efficient Agrobacterium-mediated transformation system. The gene (AtSZF2) is salt and drought stresses tolerant gene and transferred into cymbidium plants. These transgenic cymbidium plants are investigated for gene introduction by PCR and analyzed by salt and drought stresses to check its gene expression. To investigate the gene expression of AtSZF2, leaves of transgenic cymbidium plants were soaked in salt solution (200 mM NaCl). Also, transgenic cymbidium plants were kept under no watering for 6 weeks to check the expression of drought stress tolerance. As a result, wild type plants showed more damage than transgenic plants under salt treatment. Further, transgenic cymbidium plants retained green color and healthy status, while wild type plants showed no tolerance after 6 weeks of no-watering treatment.
        47.
        2012.07 서비스 종료(열람 제한)
        To characterize CBF/DREB1-homologue in rice, nine OsDREB1 genes have been identified and characterized in this lab. Among these, it was shown that OsDREB1D was induced by drought and slightly by cold stress. We found that OsDREB1A, -1D, and -1E could up-regulate OsDhn1:LUC construct in transactivation assay using rice protoplasts. Transgenic rice plants overexpressing OsDREB1D under the maize ubiquitin promoter (Ubi:OsDREB1D) revealed an enhanced stress tolerance to drought. We also generated transgenic rice of OsDREB1D under OsPOX1 promoter (OsPOX1:OsDREB1D), which is cold stress inducible preferentially in the reproductive organs of rice. We are currently examining the mechanism of the enhanced tolerance of the transgenic plants to drought stress using both molecular physiological and biochemical techniques.
        48.
        2012.07 서비스 종료(열람 제한)
        Development of transgenic plant with desirable traits to cultivated plant is one of the important procedures in plant molecular breeding. However, applicable assessment of transgenic plant in laboratorial scale is not much except cultivating transgenic plant for a whole life in field condition. Here, we analyzed chlorophyll fluorescence in three transgenic soybean lines with AtMYB44 transcription factor for assessment of photosynthetic activity under abiotic stresses such as drought. Soybean varieties used in this study were ‘Bert’ and ‘Bert’ derived three transgenic soybeans, ‘AtMYB44 CM35101’, ‘AtMYB44 CM2471’, and ‘AtMYB44 CM4481’. Analyzed five different chlorophyll fluorescence variables are maximum PSII quantum yield (QY_max), steady state PSII quantum yield (QY_Lss), steady state non-photochemical quenching (NPQ_Lss), coefficient of photochemical quenching in steady-state (Qp_Lss), and fluorescence declineratio in steady-state (Rfd_Lss). To determine main chlorophyll fluorescence variable affected by abiotic stress, principal component analysis (PCA) was conducted with five chlorophyll fluorescence variables measured from four varieties. QY_Lss and NPQ_Lss were main chlorophyll fluorescence variables to evaluate abiotic stress, particularly in drought stress. In comparison with transgenic soybean lines based on chlorophyll fluorescence variables, ‘AtMYB44 CM2471’ and ‘AtMYB44 CM4481’ are more tolerant to drought than the others. Interestingly, three transgenic soybean lines which have a same AtMYB44 gene with different regions of chromosome revealed the quite different responses of chlorophyll fluorescence to drought treatment.
        52.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        Silage corn can make good livestock feed. Anytime drought occurs during the growing season, corn grain yields will be affected. The extent of the loss will depend on stage of grow and the length of time the crop is subject to droughty conditions. During times of extended drought when grain yield potential is sever limited or nonexistent, the plants may still offer a valuable source of nutrients for livestock provided careful attention is given to how it is harvested and fed. As a rule, drought-damaged corn will have 85 to 95 percent of the feeding value of normal corn silage. Ideally, corn silage would be 60 to 70 percent moisture at harvest. Dry conditions around the state cause many corn producers to wonder about making silage from drought-damaged corn. Although silage made from drought-damaged corn is usually not as good as that made from unstress corn, drought -damaged corn can make good livestock feed. This experiment was carried out to know adaptability and forage production and quality of corn hybrid for silage at paddy field of Chonnam Province. As a result of experiment, production of silage corn reduced more than 60% compared to that of normal condition.
        53.
        2010.02 KCI 등재 서비스 종료(열람 제한)
        애기장대의 AtSIZ3(At1g08910) 유전자에 T-DNA를 삽입한 세 종류의 변이형에 저온(4℃), 고온(37℃) 및 건조스트레스를 처리하여 유묘의 생장반응과 유전자 발현을 조사하였다. 저온과 고온처리에 의해서는 야생형과 변이형간에 유묘생장에 유의한 차이를 보이지 않았다. 야생형과 변이형 식물체에 10일간의 건조스트레스를 처리하면 야생형은 재 관수에 의해 모든 식물체가 재생하였으나 변이형은 모두 고사하였고, 10일간의 건조처리로 변이형은 야생형에 비해 유묘생장이 평균 62.9%가 억제되는 것으로 나타났다. 야생형에서 AtSIZ3 유전자는 4℃의 저온처리에서 무처리를 보다 20%정도 발현이 감소하는 반면, 37℃ 고온처리에서는 3.7배, 건조처리에서는 4.5배가 증가하였다. 이 결과로 보아 AtSIZ3 유전자는 식물의 건조내성과 밀접한 연관이 있을 것으로 판단된다.
        54.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        The adverse effects of salinity and drought on soybean cultivar Hwangkeumkong were also investigated. Endogenous bioactive gibberellins GA1 and GA4, jasmonic acid (JA), abscisic acid (ABA) and salicylic acid (SA) content and pertinent changes in response to basic and double NaCl (70 mM & 140 mM) and PEG (8% & 16%) were examined. We found that plant growth and yield components significantly reduced with the application of NaCl and PEG during pre-flowering and post-flowering growth periods. The endogenous bioactive GA1 and GA4content decreased under elevated salt and drought stress. However, an insignificant increase in GA4level was noted with 8% PEG, applied during post-flowering growth stage. JA levels significantly increased with NaCl and PEG applications, but declined with elevated PEG applied during post-flowering period. SA level drastically reduced with NaCl, while insignificantly reduced with PEG. Endogenous ABA contents of leaves increased with elevated NaCl and PEG application. The endogenous bioactive GA1 and GA4, JA and ABA content of soybean leaves were analyzed through chromatograph/ mass spectrometer (GC/MS) in selected ion monitoring (SIM) mode, while SAcontent was quantified with HPLC.
        55.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        Agricultural productivity is subjected to enormous environmental constraints, particularly to salinity and drought due to their higher magnitude of adverse impacts and worldwide distribution. Silicon (Si) was found to play a favorable role in salinity and drought stress alleviation of soybean cultivar Daewonkong. All growth attributes insignificantly improved with Si nutrition. The endogenous bioactive GA1 and GA4 content increased with the application of elevated Si level both under normal and stressful condition. JA contents sharply increased with NaCl and PEG application but decreses with Si added to salt and drought stress treatments. SA level increased with NaCl and PEG and was further enhanced with Si in the salt treated plants, but reduced with the combined application of Si and PEG. The endogenous bioactive GA1 and GA4, JA and ABA content of soybean leaves were analyzed through chromatograph/mass spectrometer (GC/MS) in selected ion monitoring (SIM) mode, while SA content was quantified with HPLC.
        56.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        Jatropha (Jatropha curcas L.) is a shrub or tree belonging the genus Euphorbiaceae and is cultivated in a tropical regions including South America, South-East Asia, India and Africa. Jatropha possibly is adapted to grow in a wide range of environments for producing non-edible oils. The objective of the study is to determine effect of salt and drought on plant growth characteristics. Treatments are thus followed, 100 and 200 mM NaCl and 5 and 10% PEG. Various physiological parameters such leaf length and width, stomatal conductance, chlorophyll fluorescence and gene expression were investigated. The results showed that from 2 days onwards, 100 and 200mM NaCl treatments were significantly suppressed leaf length, width, and stomatal conductance, but 5% and 10% PEG treatments showed a similar trend of control plants. Gene expression of JcACBP of the 100 mM NaCl was slightly decreased compred to those of other treatments. These results indicate that 100 and 200 mM NaCl treatments significantly showed negative response, but 5 and 10% PEG treatments improved plant growth and development of Jatropha.
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